Since the advent of electrical apparatuses, and more importantly since the advent of electronic systems for military and aerospace applications, there has been a quest for finding a reliable and low-maintenance power source.
In the state-of-the-art, various types of power sources are in use today, including: wet and dry batteries which consist of groupings of cells which are further divided into non-rechargeable primary cells and rechargeable secondary cells; fuel cells that operate by continuously changing the chemical energy of a fuel and an oxidant to electrical energy; highly regulated electronic power supplies; and photovoltaic cells (often called solar cells) that are semiconductor devices which are capable of converting a light source, such as sunlight, directly into electricity. With photovoltaic cells, the energy in the light source is transferred to electrons in a semiconductor material. This occurs when photons strike the semiconductor material with enough energy to dislodge electrons from a fixed position in the material's valence band into the material's conduction band. A vacant electron position or "hole" is left behind at the site of the collision. Such holes can move if a neighboring electron leaves its site to fill the former hole site. An electrical current is created if these pairs of electrons and holes are separated by an intrinsic voltage in the cell material The most common technique for producing such a voltage is to create an abrupt discontinuity in the conductivity of the cell material by adding small amounts of impurities or dopants to the pure material
In all of the above power sources, there is a requirement that one or more of the active elements be periodically replenished or replaced In batteries, the dry cell is either discarded after its useful life or with nickel-cadmium cells and the like, or secondary cells, they may be recharged by an external power source. Electronic power supplies require that they be operated by an external power source. To operate fuel cells, they must use a gas i.e., oxygen or air plus bottled hydrogen. To recharge a fuel cell, the emptied tank of. hydrogen is replaced with a new one. Photovoltaic cells require no type of replenishment However, a non-constant light source, such as sunlight or an electrically powered light, is required to allow the photovoltaic cell to produce electrical power. The instant invention requires no external power source to operate nor any replenishment or replacement of elements
A search of the prior art, that included a literature search and a patent search did not disclose any articles or patents that read directly on the claims of the instand invention; however, the following U.S. patents were considered related:
______________________________________ U.S. PAT. NO. INVENTOR ISSUED ______________________________________ 4,629,821 Bronstein-Bonte 16 December 1986 4,190,465 Boling 26 February 1980 4,155,371 Wohlmut 22 May 1979 4,140,544 Sill 20 February 1979 2,259,372 Geisler 14 October 1941 ______________________________________
The Bonstein-Bonte patent discloses a photovoltaic cell (PVC) that incorporates luminescent materials. These materials absorb radiation at the lower wavelength end of the spectrum, which cannot be utilized by the PVC, but which then emit light at a longer wavelength. The PVC is responsive to these longer wavelength and thus converts the light to electrical energy.
The Boling patent discloses a solar activated luminescent solar collector structure. The structure has a light conducting medium that is physically and optically coupled on its upper surface to a thin light conducting luminescent layer. On the medium's lower surface is physically and optically coupled a photovoltaic cell (PVC). An optical mirror may be located below the PVC to reflect any escaping light that would otherwise activate the luminescent layer. In operation, light strikes the luminescent layer which has a lower index of refraction than the light conducting medium. The sunlight actives the luminescent layer and the subsequent emitted radiation is applied to the light conducting medium and on to activate the PVC.
The Wohlmut patent discloses a luminescent solar collector which employs a plurality of different types of photovoltaic cells (PVC). The luminescent solar collector has a luminescent member with a least two types of PVC's. Each type of PVC operates efficiently for the generation of electricity over a wavelength range which is different from the efficient wavelength range of the other types of PVC's present on the luminescent member. Each type of PVC also carries intermediate to it and the luminescent member a filter means which allows only light within the efficient wavelength range for that type of PVC to pass from the luminescent member into the PVC.
The Sill patent discloses a luminescent photovoltaic cell (PVC) device for converting solar or other high-level light radiation to electrical energy. The device includes a luminescent collector member having divergent upper and lower surfaces. These surfaces are divergent in at least that part or area of the collector where solar radiation enters the collector. The direction of divergence is selected to direct the internal surface angle of the reflection of collected light energy toward one or more PVC's mounted on or coupled to one or more edge surfaces of the collector.
The Geisler patent discloses a light sensitive device that is sensitive to high-level x-rays and other shortwave length radiations. The device consists of a base plate preferably of aluminum. On the plates upper surface is a selenium layer that is covered with a light permeable counter electrode which, in turn, is covered with a fluorescent substance capable of being excited by the x-ray radiations. A photovoltaic cell (PVC) is positioned relative to the source of radiation. In operation, the rays passing through the device impinge upon the fluorescent substance which is then rendered luminous. The visible rays diffused from the fluorescent substance penetrate into the PVC where electrons are released that results in a current flow.